native_client_sdk/src/libraries/third_party/pthreads-win32/sched_setscheduler.c

   1 /*
   2  * sched_setscheduler.c
   3  *
   4  * Description:
   5  * POSIX thread functions that deal with thread scheduling.
   6  *
   7  * --------------------------------------------------------------------------
   8  *
   9  *      Pthreads-win32 - POSIX Threads Library for Win32
  10  *      Copyright(C) 1998 John E. Bossom
  11  *      Copyright(C) 1999,2005 Pthreads-win32 contributors
  12  *
  13  *      Contact Email: rpj@callisto.canberra.edu.au
  14  *
  15  *      The current list of contributors is contained
  16  *      in the file CONTRIBUTORS included with the source
  17  *      code distribution. The list can also be seen at the
  18  *      following World Wide Web location:
  19  *      http://sources.redhat.com/pthreads-win32/contributors.html
  20  *
  21  *      This library is free software; you can redistribute it and/or
  22  *      modify it under the terms of the GNU Lesser General Public
  23  *      License as published by the Free Software Foundation; either
  24  *      version 2 of the License, or (at your option) any later version.
  25  *
  26  *      This library is distributed in the hope that it will be useful,
  27  *      but WITHOUT ANY WARRANTY; without even the implied warranty of
  28  *      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  29  *      Lesser General Public License for more details.
  30  *
  31  *      You should have received a copy of the GNU Lesser General Public
  32  *      License along with this library in the file COPYING.LIB;
  33  *      if not, write to the Free Software Foundation, Inc.,
  34  *      59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  35  */
  36
  37 #include "pthread.h"
  38 #include "implement.h"
  39 #include "sched.h"
  40
  41 int
  42 sched_setscheduler (pid_t pid, int policy)
  43 {
  44   /*
  45    * Win32 only has one policy which we call SCHED_OTHER.
  46    * However, we try to provide other valid side-effects
  47    * such as EPERM and ESRCH errors. Choosing to check
  48    * for a valid policy last allows us to get the most value out
  49    * of this function.
  50    */
  51   if (0 != pid)
  52     {
  53       int selfPid = (int) GetCurrentProcessId ();
  54
  55       if (pid != selfPid)
  56         {
  57           HANDLE h =
  58             OpenProcess (PROCESS_SET_INFORMATION, PTW32_FALSE, (DWORD) pid);
  59
  60           if (NULL == h)
  61             {
  62               errno =
  63                 (GetLastError () ==
  64                  (0xFF & ERROR_ACCESS_DENIED)) ? EPERM : ESRCH;
  65               return -1;
  66             }
  67           else
  68             CloseHandle(h);
  69         }
  70     }
  71
  72   if (SCHED_OTHER != policy)
  73     {
  74       errno = ENOSYS;
  75       return -1;
  76     }
  77
  78   /*
  79    * Don't set anything because there is nothing to set.
  80    * Just return the current (the only possible) value.
  81    */
  82   return SCHED_OTHER;
  83 }